"While the Outlook bulletin is certainly one to pay attention to, building a reliable exploit for this issue won't be easy," said Dustin Childs, group manager, Microsoft Trustworthy Computing. "Still, we've listed this update as one of our highest priorities for this month and encourage customers to deploy the bulletins to help ensure protection."

2004 Risks Real Again

Microsoft is putting top priority on MS13-067, which affects SharePoint Server. The most severe vulnerability is CVE-2013-1330, which allows remote code execution by malicious content sent to the server without user interaction, genuine real-time remote exploitation, said Ross Barrett, a senior manager of security engineering at Rapid 7.

"Of the 10 CVEs, one is public, but supposedly that is not CVE-2013-1330," he told us. "There is a workaround for CVE-2013-1330 related to enabling state inspection for message authentication code attributes."

The other two critical advisories require user interaction to trigger the vulnerabilities. However, Barrett noted that MS13-068 affecting Microsoft Outlook is particularly toxic because it can be triggered when users view malicious content in the Outlook preview pane.

"Apparently, we have gone back in time and the risks from 2004 are real again," he said. "This is pretty significant and administrators will have to move fast to patch this before exploits appear."

SharePoint Shops Beware

MS13-070 is concerning to Barrett because it only applies to XP and Server 2003, and those vulnerabilities tend to be less "contained" than more mature versions of Windows.

"If you are running an MS-heavy shop and have significantly invested in the back office technology of SharePoint and all its glorious services, then this month is going to be very busy for you," he said.

"There are lots of vulnerabilities to patch, many of which are high risk. Office vulnerabilities are typically mitigated by the fact that they require a user to interact with something malicious, either through an attachment or a link, in order to be exploited. But with the SharePoint that degree of mitigation may go away and other factors of defense-in-depth will come into play."

The Hardest Hit

We turned to Paul Henry, a security and forensics analyst at Lumension, to get his take on this month's Patch Tuesday. He told us this is definitely a September to remember. By way of comparison, September 2012's release only contained two bulletins -- and both were rated as important.

"We're seeing big numbers this month but there is perhaps some good news: only four patches are considered critical, two were publicly known yet Microsoft has not seen active attacks on any of the September CVEs to-date and none of them impact the current code base," Henry said.

IE, SharePoint and Outlook are hardest hit this month, Henry said, and vulnerabilities in XP and Windows 2003 were also patched -- a practice he hopes to see more of as the XP end-of-life date of April 8, 2014, nears. Windows 2003 has an end-of-life date of July 14, 2015. For anyone using XP, he said, a migration plan should be put in place if you do not already have one.